Printing press gripper mechanism



June 19, 1945. c. A. HARLESS 2,373,473

PRINTING PRESS GRIPPER MECHANISM Filed Feb. 18, 1943 2 Sheets-Sheet 1 IN V EN TOR.

June 19, 1945. c. A. HARLEss 2,373,478

PRINTING PRESS GRIPPER MECHANISM Filed Feb. 18, 1943 2 Sheets-Sheet 2 INVENTOR @lamfeo 6L Erik was,

ATTORNEY Patented June 19, 1945 PRINTING PRESS GRIPPER MECHANISM Charles Alonzo Hal-less, Oak Park, Ill., asslgnor to The Goss Printing Press Company, Chicago, 111., a corporation of Illinois Application February 18, 1943, Serial No. 476,259

3 Claims.

This invention relates to certain new and usethe appended struction, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and, together with the description, serve to explain the principles of the invention.

0f the drawings:

Fig. 1 is a vertical section through a cylinder to which the improved gripper mechanism is applied.

Fig. 2 is a fragmentary longitudinal section through the cylinder taken substantially on line 2--2 of Fig. l.

The invention is directed to providing an improved gripper in connection with the cylinders of printing presses by means of which a sheet, fed to the cylinder, may be gripped by a parallel vise-like action at the gripping point, thereby reducing the gripping force required to be applied to the movable gripping jaw to firmly grip the sheet, while at the same time relieving the sheet from undue pressure and the movable jaw from undue stresses and strains. The invention is also directed to provide a gripper mechanism in which the movable gripper is arranged radially, 'or substantially so, to the axis of the cylinder and in which the clamping action is also in a substantially radial line, thereby allowing a comparatively long resilient movable jaw to be used on which the clamping stresses and strains are small and which will give a bet-. ter and desirable elastic clamping pressure on the sheet. The invention is further directed to provide a gripper mechanism in which the movable resilient jaw is supported independently of its actuating shaft and adapted to be operated from the shaft in suchmanner as to eliminate the difficulties encountered when the gripper is supported by and subjected to torsional strains in the action of the shaft; The invention is still further directed to provide novel operating means for operating the movable gripper from a rock'shaft which allows a long unitary leaf spring-gripper or laminated leaf spring gripper with long leaves to be used, with the advantages stated, and that of allowing an elastic gripping pressure to be obtained, and while maintaining the rock shaft at such a distance from the axis of the cylinder as to enable a strong clamping pressure to be applied even in the use of the gripper on small cylinders. The present invention also provides a gripper mechanism which is adapted for use on difl'erent sizes of cylinders, and is particularly adapted for efficient use on small cylinders, and which will grip the sheet or sheets fed to it with substantially uniform pressure regardless of the number of sheets fed to the cylinder.

Heretofore it has been customary to mount a unitary Or laminated spring gripper on an actuating rock shaft arranged to clamp the sheet against a portion of the outer periphery of the cylinder or a radial jaw surface on the cylinder. With this construction, however, as the grippers are turned to grip the sheet or sheets fed to the cylinder the supporting and actuating shaft is subjected to torsional strains, which causes the grippers to be displaced relative to each other. Generally eight or ten such gripper fingers are mounted on each shaft and it is very difficult to adjust these grippers so that they will simultaneously grip the sheet. Also, once the grippers have been so adjusted, they get out'of adjustment in a very short time, thereby causing some of the gripper fingers to bear very hard against the cylinder while others of the fingers do not touch the cylinder or touch it very lightly. The mounting of the gripper fingers on the actuating rock shaft furthermore reduces the length and efiectiveness of g ripper fingers which may be applied to small cylinders. These and other difliculties are avoided by the present invention.

It is to be understood that the foregoing gen- I eral description and the following detailed description are exemplary and explanatory of the invention, but are not restrictive thereof.

Referring now in detail to the presehtpreferred embodiment of the invention, the gripper mechanism is shown as applied to, and used in connection with, a printing press cylinder I0 having a hub portion II, a peripheral rim portion l2, and spokes I 3 or the like connecting said hub and rim portions. The rim portion I! of this cylinder is provided with a gap or slot I! for the reception of the sheet or sheets to be gripped, one of the walls of the slot being formed or constructed to provide a stationary gripping jaw l5 while the opposed wall of the slot is suitably shaped to provide an abutment surface I6. The surfaces l5 and I6 are arranged substantially in parallel relation and radially of the cylinder;

Gripper mechanism is mounted on the cylinder for cooperation with the jaw 15.. As embodied, the gripper mechanism comprises a plurality of resilient gripper fingers I'I each mounted at one end on the hub of the cylinder and extending radially outward therefromwith its free end disposed in the slot [4 for movement toward and from the jaw l5, whereby the fingers H are adapted when moved to gripping position to grip a sheet or group of sheets 11' between them and the jaw I5. Each of the fingers I! may be formed of a single substantially straight and fiat leaf spring, or "it may be of laminated type and formed of a plurality of superposed leaf spring members of the same or graduated lengths and suitably secured together. In their normally retracted positions the fingers I! rest close to the abutment surface [6 for the free introduction of the sheet or sheets 11' between them and the jaw I5.

Means are providedfor mounting the gripper fingers I! on the hub II and effecting the movements of said fingers into and out of gripping position. As shown, each finger l'I bears at its inner end against a supporting lug I8 and shoulder l 9 on the hub and is clamped in position by a clamp plate and one or more machine screws 2|. Supported in the cylinder at the side of the fingers at which the abutment surface 16 is located is a rock shaft 22 carrying a plurality of cam-like rocker-arms 23. One of these arms v ating mechanism, and as the gripper are supported independently of the shaft no torsional strains to cause their displacement can occur. Furthermore, as the construction employed allows comparatively long fingers to be used, even on a' small cylinder, the fingers themselves operate at all times under low stresses, so that great durability of the fingers is insured.

The invention in its broader aspects is not limited to the specific mechanisms shown and described, but departures may be made therefrom within the scope of the appended claims without departing from the principles of the invention and without sacrificing its chief advantages.

Having thus described my invention, I claim:

1. A gripping device including in combination a cylinder having a hub portion, a peripheral portion spaced therefrom and provided with a slot, and a stationary jaw on one of the walls of the slot, a co-acting resilient leaf spring disposed within the cylinder substantially radially between its hub and periphery and fixed at one end to the hub and having its opposite end free and in the form of a gripping jaw, and arranged for movement in the slot between the stationary jaw and the opposed wall of the slot, a rock shaft mounted within the cylinder, a rocker arm actuated by said shaft and a deflecting finger carried by the rocker arm for effecting movements of the resilient jaw toward and into gripping contact with the stationary jaw under urge of the finger, in one direction and permitting return of the free gripping jaw to a. non-gripping position under resiliency of the spring, in another direction.

2. A gripping device including in combination a cylinder, a stationary jaw carried thereby, a resilient leaf spring rigidly secured at one end directly to the cylinder but being otherwise free for flexion between its ends and having its other end arranged to form a free gripping jaw normally spaced from and movable toward and from or screw 25. These collars may be turned on the shaft to adjust or set the rocker arms to adapt them to vary the throw of the fingers and cause them to bear with the same or different degrees of pressure on the sheet or sheets l1.

Normally the free ends of the fingers I! rest close to the surface l6 and the medial portions of the fingers lie in contact with the cam surfaces at the free ends of the arms 23. The shaft in practice is periodically rocked through a small angle in the usual manner, and this may be done by any standard, well known cam mechanism or other suitable mechanism (not shown). In

their movement in one direction the rocker armsforce the fingers toward the jaw 15 to grip the sheet or sheets and in their movement in the opposite direction the rocker arms permit the fingers to move backward to release the sheets. It will be observed that the construction is such that at the gripping moment the gripping faces of the fingers and jaw 15 will be parallel with each other and will clamp the sheet or sheets on a radial line in a vise-like manner, insuring the firm and secure gripping of the sheets. As the gripping fingers may independently yield the respective fingers may accommodate themselves to sheets or products varying in thickness without excessive strain on the fingers or their operthe stationary jaw, and a pressure producing device mounted within the cylinder and movable toward and from the spring for directly exerting a bending pressure on the spring to deflect the free gripping jaw out of its normal position toward and into gripping position with relation to the stationary jaw and for thereafter relieving the pressure to permit the free gripping jaw to move by the resiliency of the spring back to non-gripping position.

3. A gripping device including in combination a cylinder having a hub portion, a peripheral portion spaced therefrom and provided with a slot, and a stationary jaw on one of the walls of the slot, a co-acting resilient leaf spring disposed within the cylinder substantially radially between its hub and periphery and fixed at one end to the hub and having its opposite end free and in the form of a gripping jaw, arranged for movement in the slot between the stationary jaw and the opposed wall of the slot, and an oscillatable pressure producing member mounted within the cylinder for effecting movement of the resilient jaw toward and into gripping coaction with the stationary jaw under pressure of said members in one direction and permitting return direction.

CHARLES ALONZO HARIESS. 

